[FIR] Add constraint to flexible type for declared argument for java parameter

compiler/fir/analysis-tests/testData/resolve/problems/flexibleTypeVarAgainstNull.kt

@@ -7,10 +7,5 @@ public class JavaClass<T> {
 
 // FILE: main.kt
 fun main() {
-    // See https://github.com/JetBrains/kotlin/commit/437a26684d3529ee2cfdbe54e59d50f4a6f0a611#diff-ba68311bbe28b71196c36a6246000382L176
-    // In simplifyLowerConstraint, we add constraint Nothing? <: T!, approximating it with Nothing? <: T
-    // But before it we already had T <: String from the explicit types
-    // That lead us to constraint contradiction: Nothing? !<: String
-    // We need to discuss the commit above at some point
-    <!INAPPLICABLE_CANDIDATE!>JavaClass<!><String>(null).<!UNRESOLVED_REFERENCE!>foo<!>().<!UNRESOLVED_REFERENCE!>length<!>
+    JavaClass<String>(null).foo().length
 }

compiler/fir/analysis-tests/testData/resolve/problems/flexibleTypeVarAgainstNull.txt

@@ -1,4 +1,4 @@
 FILE: main.kt
     public final fun main(): R|kotlin/Unit| {
-        <Inapplicable(INAPPLICABLE): [/JavaClass.JavaClass]>#<R|kotlin/String|>(Null(null)).<Unresolved name: foo>#().<Unresolved name: length>#
+        R|/JavaClass.JavaClass|<R|ft<kotlin/String, kotlin/String?>!|>(Null(null)).R|FakeOverride</JavaClass.foo: R|ft<kotlin/String, kotlin/String?>!|>|().R|kotlin/String.length|
     }